Symbolic and non symbolic numerical representation in adults with and without developmental dyscalculia

Furman Tamar, Rubinsten, Rubinsten Orly

Description

The question whether Developmental Dyscalculia (DD; a deficit in the ability to process numerical information) is the result of deficiencies in the non symbolic numerical representation system (e.g., a group of dots) or in the symbolic numerical representation system (e.g., Arabic numerals) has been debated in scientific literature. It is accepted that the non symbolic system is divided into two different ranges, the subitizing range (i.e., quantities from 1-4) which is processed automatically and quickly, and the counting range (i.e., quantities larger than 4) which is an attention demanding procedure and is therefore processed serially and slowly. However, so far no study has tested the automaticity of symbolic and non symbolic representation in DD participants separately for the subitizing and the counting ranges. Methods DD and control participants undergo a novel version of the Stroop task, i.e., the Enumeration Stroop. They were presented with a random series of between one and nine written digits, and were asked to name either the relevant written digit (in the symbolic task) or the relevant quantity of digits (in the non symbolic task) while ignoring the irrelevant aspect. Result DD participants, unlike the control group, didn't show any congruency effect in the subitizing range of the non symbolic task. Conclusion These findings suggest that DD may be impaired in the ability to process symbolic numerical information or in the ability to automatically associate the two systems (i.e., the symbolic vs. the non symbolic). Additionally DD have deficiencies in the non symbolic counting range.

Informations

• Publié par: biomed
• Publié le: 01 janvier 2012
• Nombre de lectures: 6
• Langue: English
• Poids de l'ouvrage: 1 Mo

Extrait

Furman and Rubinsten Behavioral and Brain Functions 2012, 8 :55 http://www.behavioralandbrainfunctions.com/content/8/1/55

R E S E A R C H Symbolic and non symbolic numerical representation in adults with and without developmental dyscalculia Tamar Furman and Orly Rubinsten *

Open Access

Abstract Background: The question whether Developmental Dyscalculia (DD; a deficit in the ability to process numerical information) is the result of deficiencies in the non symbolic numerical representation system (e.g., a group of dots) or in the symbolic numerical representation system (e.g., Arabic numerals) has been debated in scientific literature. It is accepted that the non symbolic system is divided into two different ranges, the subitizing range (i.e., quantities from 1-4) which is processed automatically and quickly, and the counting range (i.e., quantities larger than 4) which is an attention demanding procedure and is therefore processed serially and slowly. However, so far no study has tested the automaticity of symbolic and non symbolic representation in DD participants separately for the subitizing and the counting ranges. Methods: DD and control participants undergo a novel version of the Stroop task, i.e., the Enumeration Stroop. They were presented with a random series of between one and nine written digits, and were asked to name either the relevant written digit (in the symbolic task) or the relevant quantity of digits (in the non symbolic task) while ignoring the irrelevant aspect. Result: DD participants, unlike the control group, didn't show any congruency effect in the subitizing range of the non symbolic task. Conclusion: These findings suggest that DD may be impaired in the ability to process symbolic numerical information or in the ability to automatically associate the two systems (i.e., the symbolic vs. the non symbolic). Additionally DD have deficiencies in the non symbolic counting range.

Introduction numerical systems and then portray the rationale behind Developmental dyscalculia (DD) is a specific disorder in the method used to explore whether DD adults are defi- numerical and mathematical abilities, with a neuro- cient in one or both of these systems. anatomical source [1-3], for meta-analyses see: [4]. There is a continuous debate in scientific literature on Non symbolic numerical representations the ability of people with DD to represent symbolic (e.g.,  Certain numerical skills, unlike readi Arabicnumerals)andnon-symbolic(e.g.,agroupof withoutformalteaching.Theseskill n s g a s r k e ills c , om de m ve o l n o l p y dots with different quantities) numerical information. In  , non mbolic, and thecurrentstudyweexaminedspecificallywhetherDD s a y tt s r t i e b m ut [ e 6 d ,7 t ]. o S a t n ud a ie n s al s o h g owthat sy infants,ande a v p en pr a o n x i i m m a a l t s e , adults are deficient in their ability to automatically  display several basic numerical skills such as counting, process one or both of the systems of numerical repre-  ad infant n sentation.Forthispurpose,weusedanovelversionof fou d n in d g, to an b d e c n o o m t p o a n ri l n y g c [ a 8 p ]. ab S l p e ec o i f fic di a s ll c y e , rnings s m h a a ll ve o b bj e e e ct the Stroop task [5] which we called enumeration Stroop.  e ts [9,10] de- Inthefollowingintroduction,wefirstdescribethesetwo s p e e t n s d ( i o n b g je o c n t v t i r s a u c a k l i - n s g pa s t y i s a t l e p m r ) o , ce b s u s t in a g ls c o a l p a a r b g ilit s i e es[11]. * Correspondence: [e-mail] DDisfre i q c u al en p t r l o y c a e t s t s r e i s b , u s t u ed ch to as a im de p fi a c ir it ed in u t n h d e e s r e sta bas d i i c n , g in o - f Department of Learning Disabilities; Edmond J. Safra Brain Research Center nate numer n for the Study of Learning Disabilities, University of Haifa, Haifa, Israel the meaning of numbers or impaired quantity representation © 2012 Furman and Rubinsten; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.